1. Field of the Invention
The present invention relates to a humidity moisture exchanger (HME) usable in conjunction with a standard ventilator machine or the like. More specifically, the present invention relates to an HME capable of permitting the uninhibited passage of fluid, including gasses and aerosols, without being detached from the ventilator circuit.
2. Description of the Prior Art
It is common to place a Humidity Moisture Exchanger (HME) within a tube connecting a patient to a ventilator machine or the like. The HME becomes a part of the ventilator circuit, and it acts as a filtering mechanism to trap heat and moisture that would otherwise be lost during the artificial ventilation. The use of an HME is especially prevalent for patients utilizing endotracheal or tracheostomy tubes.
One invention pertaining to a filtering mechanism for a respiratory breathing system is disclosed in UK Patent Application GB 2 231 509 A, published on Nov. 21, 1990. The filtering mechanism of this invention includes a housing having an inlet port and an outlet port. This housing is constructed from two parts, each including an inner peripheral wall. When the two parts of the housing are affixed together, a filter member is secured between the inner peripheral walls of each part. During use of the respiratory breathing system, the filter member remains in a position directly in the path of air traveling between the inlet and outlet ports of the housing.
A similar device is illustrated in European Patent Application No. 0 265 163 A2 published on Apr. 27, 1988. This device is a heat and moisture exchanger having first and second ports secured together to form a housing. An air passageway is created by inlet and outlet ports integral with the housing. A filter member is affixed within the housing so as to permanently block the air passageway.
Another similar device is disclosed in International Patent Application No. WO 91/19527 published on Dec. 26, 1991. This invention is a device to be incorporated in the medical duct supplying air and/or gasses to a patient. It includes a filter member permanently affixed between inlet and outlet portions of a housing. A resistance is positioned within a metal sleeve spaced from the filter member. This resistance is utilized to control both the temperature and the humidity of the air passing through the filter member.
One problem with the above filtering mechanisms is that they block the passage of aerosols or other medications passed to the patient through the ventilator circuit. Therefore, to adequately pass aerosols and medications to the client, it is necessary to completely remove the filtering mechanism from the ventilator circuit. Such removal results in an undesired pressure drop within the ventilator circuit, and it increases the likelihood of a passage of contaminants either to or from the patient.
A non-filtering mechanism relevant to the instant invention is U.S. Pat. No. 4,673,386, issued to Mark G. Gordon on Jun. 16, 1987. This patent discloses a blood sampler device having a housing with first and second ports. The first port is connectable to a patient blood supply, and the second port is connectable to the injection site. Retractably positioned within the housing is a piston attached to a sealing member, which may be positioned to impede the passage of fluid through the housing.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.